#include "bundle.h"
#include <stdlib.h>
#include "macros.h"
#include <unistd.h>
#include <string.h>

typedef struct
{
	SDL_RWops *handle;
	BundleFile *file;
	Uint32 pos;
} RWOpsBundle;


int bnd_open(Bundle *bundle, const char * filename)
{
	SDL_RWops *rw = SDL_RWFromFile(filename, "rb");
	
	if (rw)
	{
		if (!bnd_open_RW(bundle, rw))
		{
			SDL_RWclose(rw);
			return 0;
		}
	
		bundle->close_handle = true;
	
		//SDL_FreeRW(rw);
		return 1;
	}
	else
	{
		warning("Can't open bundle '%s'", filename);
		return 0;
	}
}


int bnd_open_RW(Bundle *bundle, SDL_RWops *ctx)
{
	memset(bundle, 0, sizeof(*bundle));
	
	char sig[5] = { 0 };
	SDL_RWread(ctx, sig, strlen(BND_SIG), sizeof(char));
	
	if (strncmp(sig, BND_SIG, strlen(BND_SIG)) != 0)
	{
		warning("Bundle sig does not match '"BND_SIG"'");
		return 0;
	}
	
	SDL_RWread(ctx, &bundle->flags, 1, sizeof(bundle->flags));
	
	FIX_ENDIAN(bundle->flags);
	
	if (bundle->flags != 0)
		warning("Unsupported bundle mode");
	
	SDL_RWread(ctx, &bundle->n_files, 1, sizeof(bundle->n_files));
	
	FIX_ENDIAN(bundle->n_files);
	
	bundle->file = calloc(sizeof(bundle->file[0]), bundle->n_files);
	
	Uint32 origin = 0;
	
	for (int i = 0 ; i < bundle->n_files ; ++i)
	{
		char name[BND_MAX_NAME_SIZE];
		memset(name, 0, sizeof(name));
		
		char c;
		int l = 0;
		
		do
		{
			SDL_RWread(ctx, &c, 1, 1);
			if (l < BND_MAX_NAME_SIZE-1)
			{
				name[l] = c;
				++l;
			}
			else
				warning("Bundle name too long");
		}
		while (c);
		
		bundle->file[i].name = strdup(name);
		SDL_RWread(ctx, &bundle->file[i].size, 1, sizeof(bundle->file[i].size));
		FIX_ENDIAN(bundle->file[i].size);
		bundle->file[i].offset = origin;
		origin += bundle->file[i].size;
	}
	
	Uint32 header_size = SDL_RWtell(ctx);
	
	for (int i = 0 ; i < bundle->n_files ; ++i)
	{
		bundle->file[i].offset += header_size;
	}
	
	bundle->handle = ctx;
	
	debug("Opened bundle (%d files)", bundle->n_files);
	
	return 1;
}


void bnd_free(Bundle *bundle)
{
	for (int i = 0 ; i < bundle->n_files ; ++i)
	{
		free(bundle->file[i].name);
	}
	
	if (bundle->close_handle) 
	{
		SDL_RWclose(bundle->handle);
	}
	
	free(bundle->file);
	memset(bundle, 0, sizeof(*bundle));
}


static Sint64 bnd_seek(struct SDL_RWops *context, Sint64 offset, int whence)
{
	RWOpsBundle *b = context->hidden.unknown.data1;
	
	switch (whence)
	{
		case SEEK_SET:
		SDL_RWseek(b->handle, b->file->offset + offset, SEEK_SET);
		break;
	
		case SEEK_CUR:
		SDL_RWseek(b->handle, offset, SEEK_CUR);
		break;
		
		case SEEK_END:
		SDL_RWseek(b->handle, b->file->offset + b->file->size - offset, SEEK_SET);
		break;
	}
	
	if (SDL_RWtell(b->handle) < b->file->offset)
		SDL_RWseek(b->handle, b->file->offset, SEEK_SET);
	if (SDL_RWtell(b->handle) > b->file->offset + b->file->size)
		SDL_RWseek(b->handle, b->file->offset + b->file->size, SEEK_SET);
		
	return b->pos = (SDL_RWtell(b->handle) - b->file->offset);
}


#if SDL_VERSION_ATLEAST(1,3,0)
static size_t bnd_read(struct SDL_RWops *context, void *ptr, size_t size, size_t num)
#else
static int bnd_read(struct SDL_RWops *context, void *ptr, int size, int num)
#endif
{
	RWOpsBundle *b = context->hidden.unknown.data1;
	
	SDL_RWseek(b->handle, b->file->offset + b->pos, SEEK_SET);
	
	if (size * num > b->file->size - (SDL_RWtell(b->handle) - b->file->offset))
		num = (b->file->size - (SDL_RWtell(b->handle) - b->file->offset)) / size;
	
	b->pos += size * num;
	
	return SDL_RWread(b->handle, ptr, size, num);
}


static int bnd_close(struct SDL_RWops *context)
{
	RWOpsBundle *b = context->hidden.unknown.data1;
	free(b);
	SDL_FreeRW(context);
	return 0;
}


SDL_RWops *SDL_RWFromBundle(Bundle *bundle, const char *filename)
{
	SDL_RWops *rwops;
	RWOpsBundle * b = calloc(1, sizeof(RWOpsBundle));
	b->handle = bundle->handle;
	
	for (int i = 0 ; i < bundle->n_files ; ++i)
	{
		if (strcmp(bundle->file[i].name, filename) == 0)
		{
			b->file = &bundle->file[i];
			break;
		}
	}
	
	if (!b->file)
	{
		warning("SDL_RWFromBundle file %s not found", filename);
		free(b);
		return NULL;
	}
		
	rwops = SDL_AllocRW();
	
	if (rwops != NULL) 
	{
		rwops->seek = bnd_seek;
		rwops->read = bnd_read;
		rwops->write = NULL;
		rwops->close = bnd_close;
		rwops->hidden.unknown.data1 = b;
		
		rwops->seek(rwops, 0, SEEK_SET);
	}
	else
	{
		free(b);
	}
	
	return rwops;
}


int bnd_exists(const Bundle *bundle, const char *filename)
{
	for (int i = 0 ; i < bundle->n_files ; ++i)
	{
		if (strcmp(bundle->file[i].name, filename) == 0)
		{
			return 1;
		}
	}
	
	return 0;
}


